This 4.5mm Delos telescope eyepiece by Tele Vue will provide exceptionally clear, high-magnification views of the cosmos. The 4.5mm model, like all Delos eyepieces, offers a long 20mm eye relief for comfortable views even while wearing eyeglasses. Not only is this a relatively high-power telescope eyepiece, but it provides a wide, 72° field of view for immersive observations.

The Tele Vue Delos eyepiece design was conceived as a narrower field alternative to Ethos eyepieces. Reducing the field to 72° allowed freedom to increase eye-relief, while controlling pupil aberrations, all without making the eyepiece too large. With Ethos performance standards as benchmarks, the Delos design achieves full field sharpness, virtually perfect theta distortion mapping, and color neutrality. Image fidelity is maximized utilizing glass matched multi-coatings and anti-reflection surfaces throughout the eyepiece. Contrast is further enhanced with a new continuously adjustable height eyeguard system that can be locked in any position. Since the Delos eye-lens measures a quite large 35mm in diameter, they prevent stray light from reflecting off the first surface and prevent extraneous light from entering your eye to pay off in a nice increase in perceived contrast. The eyeguard's sliding action allows for positioning the soft rubber eyeguard at the ideal height to suit the observers preference. Indicator marks on the eyepiece body are handy reference guides for setting your perfect position. The eye-guard can also rotate for Dioptrix users.

Warranty

This product is serviced and supported by its manufacturer according to the terms and conditions included in the packaged product. Orion's limited warranty does not apply. Please contact the manufacturer directly for technical support.

Design

Different eyepiece designs allow for a wide range of features, depending on the needs of the observer. Orthoscopic and Plossl designs can provide a great quality image with a standard field of view, but may be difficult to use at higher powers while wearing glasses due to the short eye-relief. Long eye-relief designs have more elements and can be more expensive, but work very well with glasses, even at higher powers. Wide angle designs provide a larger view of the sky at the same power as a standard eyepiece. More complex designs can combine all these attributes together in a single eyepiece.

Apparent field of view

The edge-to-edge angular diameter of the image displayed in a binocular as seen by the eyes of the observer. It is an inherent specification for a given binocular design. The "angular diameter" of an object is defined as the angle an object makes (subtends) as seen by an observer.

Eye relief

The distance, measured in millimeters, between the observer's eye and the eyepiece lens in which the entire field of view remains visible. Eye relief varies with the optical design but generally increases with decreasing magnification. Long eye relief is advantageous for observers who wear glasses, as they don't have to put their eye directly on the eyepiece to see the entire field of view, nor do they have to remove their eyewear.

Coatings

Binocular lenses and prisms are often coated with anti-reflective material to minimize light loss as light travels through the multiple optical surfaces of a typical binocular. Coatings help maximize the amount of light transmitted through each glass surface of a binocular, so as much light as possible reaches the observer's eyes to provide a bright and sharp image.

Good lenses are at least "fully coated," with a single layer of magnesium fluoride coating applied to each air-to-glass lens surface. Multiple layers of coatings are even more effective; the term "multi-coated" means one or more air-to-glass lens surface has multiple coatings. "Fully multi-coated" optics are even better, meaning all lens surfaces have multiple layers of anti-reflective coatings applied for maximum light transmission and optimal image quality.

Parfocal

Field stop diameter

The field stop is a mechanical ring in the eyepiece which provides the sharp edge to the field of view when looking through the eyepiece. The field stop diameter greatly affects the apparent field of view of the eyepiece; the larger the field stop diameter, the larger the apparent field of view is.

Barrel security recess

The barrel security recess is a shallow groove or depression cut into the 1.25" or 2" barrel of the eyepiece. In the event the thumb screw holding the eyepiece in the focuser becomes slightly loose, the eyepiece will not fall out because the tip of the thumb screw will catch on the lip of the security groove.

Warranty

This warranty gives you specific legal rights. It is not intended to remove or restrict your other legal rights under applicable local consumer law; your state or national statutory consumer rights governing the sale of consumer goods remain fully applicable.

Limited lifetime

Shipping Info

Orders received by noon Pacific Time for in-stock item the same business day. Order received after noon will ship the next business day. When an item is not in-stock we will ship it as soon as it becomes available. Typically in-stock items will ship first and backordered items will follow as soon as they are available. You have the option in check out to request that your order ship complete, if you'd prefer.

SHIPPING RESTRICTIONS APPLY FOR THIS PRODUCT

This product is available to ship Standard delivery within the 50 US states, APO/DPO/FPO addresses and US territories/protectorates. Delivery is not available to Canada.

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At Orion, we are committed to sharing our knowledge and passion for astronomy and astrophotography with the amateur astronomy community. Visit the Orion Community Center for in-depth information on telescopes, binoculars, and astrophotography. You can find astrophotography "how to" tips and share your best astronomy pictures here. Submit astronomy articles, events, and reviews, and even become a featured Orion customer!